The future of solar power generation is in these flexible solar cells, Das said.
He and his research team are investigating various nano-materials to fabricate the
third-generation solar cells. The researchers hope to develop a superior photovoltaic
technology that produces cheaper and more efficient solar cells.

“The most fascinating part of doing this research is the enormous potential that this
new technology offers, such as integrating flexible solar cells on wearable electronics,
backpacks and self-charging cell phones and electricity-generating layers on windows,
especially on skyscrapers, and solar power’s ability to supply a large amount of clean,
renewable and cheap energy for the future,” said David Danilchuk, an electrical engineering
major who is an undergraduate research assistant on the project.

In the laboratory, the research team fabricated the solar cells' multiple nano-structured
layers using a unique manufacturing process. Specialty instruments, like electron
microscopes, as well as X-ray spectroscopy techniques and precision electronic measurement
systems, enable the research team to investigate and better understand the cells’
behavior.

Baker Nour, an electrical engineering student and member of the research team, explained
that the fabrication process developed by the team can produce these solar cells on
plastic substrates to create flexible solar cells — one of the most advanced ideas
in solar technology today.

In practice, these flexible solar panels can be beneficial after catastrophic storms.
Disaster relief personnel could transport rolled-up solar panels to produce portable
power on site, Das explained. Commercial building developers also are eyeing smart
building applications, like transparent solar panels for windows, so skyscrapers can
generate solar power and be more energy efficient.

Innovative materials and efficiencyCurrent commercial solar panels use first-generation silicon solar cells, which are
expensive, fragile and bulky, limiting their portability, according to Das.

The most promising materials systems for future generation solar cells, according
to Das, are the materials that his research team applies in their fabrication – an
ultra-thin hybrid Perovskite noncrystalline film. Rather than using expensive silicon, they fabricate their solar cells on cheap glass
substrates like those in windows and beverage bottles.

The team plans to explore the fabrication process so they can develop solar cells
on flexible plastics or metal foils, without requiring expensive materials, million-dollar
equipment or scientific-grade clean rooms.

“For the past 20 years, efficiency of silicon solar cells could not be improved much
after substantial research efforts globally,” Das said. He explained that silicon
is not a good light absorber, and new technologies are needed to create high-efficiency
cells at a lower cost. The new bandgap-engineered Perovskite crystals, which his team
is investigating, can absorb a wider spectrum of sunlight compared to silicon, on
a film that is 200 times thinner than silicon cells.

Implications for their research are still months away, but the team is confident that
they will soon improve solar cells to attain higher efficiency, without the latest
high-tech equipment or costly raw materials.

Cutting CostsA major goal for their research is to substantially reduce the cost of producing solar
cells.

Typically, solar cells are fabricated in a clean room, a controlled environment for
manufacturing electronics that is free of dust or other contaminants. Even without
a clean room, Das and his team are able to fabricate this next generation of solar
cells and test their newly hatched cells.

“In the past 20 to 30 years of studying solar energy, researchers worldwide have learned
how to cut costs tenfold,” Das said. “The raw materials used for the third-generation
solar cells are less expensive than the electronic-grade silicon.”

A cutback in both material and fabrication costs means a significant reduction in
the overall cost to produce electricity, ultimately saving consumers money.

“Our long-term goal is to bring the cost down to less than 10 cents per watt,” Das
said. In the U.S., silicon solar cells currently cost about 30 cents per watt.

Das predicts that by 2040 solar power will become mainstream as researchers develop
technologies to more efficiently use available space for power generation and solar
cells become cheaper.

“For us, it's exciting to be able to contribute to the field by sharing the knowledge
that we obtain from our research and help advance the solar industry,” Danilchuk added.

A leader in innovative teaching and learning, Kennesaw State University offers more than 150 undergraduate, graduate and doctoral degrees to its more than 35,000 students. With 13 colleges on two metro Atlanta campuses, Kennesaw State is a member of the University System of Georgia and the third-largest university in the state. The university's vibrant campus culture, diverse population, strong global ties and entrepreneurial spirit draw students from throughout the region and from 92 countries across the globe. A Carnegie-designated doctoral institution, it is one of the 50 largest public institutions in the country. For more information, visit kennesaw.edu.